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D N Love

Publications and source records attributed to D N Love.

At least 37 records · Page 2Linked to original sources
PubMed2000

Bacteriological warfare amongst cats: what have we learned about cat bite infections?

Cat bite infections are one of the most common infectious diseases presenting to veterinary practices and to emergency rooms at human hospitals. This review describes the disease in humans and cats, the origin of organisms involved in cat bite abscesses and the importance of selected organisms such as members of the genus Porphyromonas in the disease. It also discusses future directions, the importance of identifying significant organisms and why an understanding of antimicrobial susceptibility patterns is of consequence to the outcome of the disease in humans and cats.

Abscess↗
PubMed2000

Serum antibody responses of cats to soluble whole cell antigens of feline Porphyromonas gingivalis.

The whole cell soluble antigens of two strains (VPB 3457 and VPB 3492) of feline Porphyromonas gingivalis were analysed by Western blotting using serum taken from 40 domestic cats with various grades of periodontal disease. Five strongly immunogenic protein bands (70, 34, 27, 24 and 19kDa) from VPB 3457 and seven from VPB 3492 (58, 44, 34, 27, 25, 24 and 21kDa) were selected for further study. A significant positive correlation was found between the serum antibody response to the 70, 34, 27, 24 and 19kDa bands of VPB 3457 and the 58, 44, 25, 24 and 21kDa bands of VPB 3492 and the overall periodontal grade. A significant positive correlation was also found between the serum antibody response to the 24kDa band of VPB 3457 and the total colony forming units of P. gingivalis. N-terminal sequencing of the 44kDa band of VPB 3492 showed 75% identity with the translated amino acids from the hag A (haemagglutinin) gene of a human strain of P. gingivalis and N-terminal amino acid sequence of the 27kDa band of VPB 3457 showed 88% identity with the amino acid sequences translated from DNA of purported genes coding for variously named proteinases of human strains of P. gingivalis.

Amino Acid Sequence↗
PubMed2000

A prime-boost immunization strategy with DNA and recombinant baculovirus-expressed protein enhances protective immunogenicity of glycoprotein D of equine herpesvirus 1 in naïve and infection-primed mice.

The immunogenicity and protective efficacy afforded by intramuscular inoculation of plasmid DNA encoding equine herpesvirus 1 (EHV-1) glycoprotein D (gD) followed by EHV-1 gD expressed by a recombinant baculovirus was assessed in a murine model of EHV-1 respiratory infection. Compared with mice inoculated with DNA or protein only, mice inoculated with the combination of gD DNA and protein had enhanced ELISA and neutralizing antibody titres to EHV-1 and had accelerated clearance of virus from lungs following challenge infection. The enhanced protective effects of this consecutive immunization were also evident in mice which had a previous infection with EHV-1 and had pre-existing antibodies. The T-helper 1 (Th1) type of immune response induced by EHV-1 gD DNA was maintained after the protein boost, despite the gD protein alone appearing to direct a Th2 response.

Animals↗
PubMed2000

Characterisation of IE and UL5 gene products of equine herpesvirus 1 using DNA inoculation of mice.

The equine herpesvirus 1 (EHV-1) strain HVS25A regulatory genes IE and UL5, encoding homologues of herpes simplex virus 1 (HSV-1) ICP4 and ICP27 respectively, were cloned into a eukaryotic expression vector and the DNA injected intramuscularly into mice. Antibodies produced in this way detected the IE or UL5 gene products as diffuse material in nuclei of RK13 cells transfected with the individual genes but as discrete punctate or large aggregates in RK13 cells infected with EHV-1. Western blotting on EHV-1 infected RK13 cells showed multiple IE products of 120-200 kDa and a UL5 product of 52 kDa. Inoculation with plasmids expressing EHV-1 IE or UL5 provided limited protection against EHV-1 challenge in mice as determined by increased virus clearance from lungs on day 2 post-challenge and a reduction in severity of lung histopathology. However, this protection was relatively weak compared with that provided by inoculation of DNA encoding EHV-1 glycoprotein D (gD), possibly reflecting the importance of neutralising antibody in this model.

Animals↗
PubMed2000

EHV-1 glycoprotein D (EHV-1 gD) is required for virus entry and cell-cell fusion, and an EHV-1 gD deletion mutant induces a protective immune response in mice.

Insertional mutagenesis was used to construct an equine herpesvirus 1 (EHV-1) mutant in which the open reading frame for glycoprotein D was replaced by a lacZ cassette. This gD deletion mutant (delta gD EHV-1) was unable to infect normally permissive RK cells in culture, but could be propagated in an EHV-1 gD-expressing cell line (RK/gD). Phenotypically complemented delta gD EHV-1 was able to infect RK cells, but did not spread to form syncytial plaques as seen with wild type EHV-1 or with delta gD EHV-1 infection of RK/gD cell cultures. Therefore EHV-1 gD is required for virus entry and for cell-cell fusion. The phenotypically complemented delta gD EHV-1 had very low pathogenicity in a mouse model of EHV-1 respiratory disease, compared to a fully replication-competent EHV-1 reporter virus (lacZ62/63 EHV-1). Intranasal or intramuscular inoculation of mice with delta gD EHV-1 induced protective immune responses that were similar to those elicited in mice inoculated with lacZ62/63 EHV-1 and greater than those following inoculation with UV-inactivated virus.

Animals↗
PubMed2000

The association of two recombinant proteinases of a feline strain of Porphyromonas gingivalis with periodontal disease in cats.

Serum from 40 domestic cats with various grades of periodontal disease was used to probe two recombinant functional proteinases from feline strain VPB 3457 of Porphyromonas gingivalis expressed in E. coli. One recombinant proteinase (VPB 2856) was constructed using polymerase chain reaction and had 91% DNA identity with the prtC collagenase gene of the human type strain of P. gingivalis, while the other proteinase (VPB 2814) was isolated from a size selected genomic library and had an amino-terminal sequence with no significant identity with deposited sequences. Thirteen of 40 cats showed a serum antibody response to VPB 2856 using Western immunoblot detection. All the 13 cats had an overall periodontal grade of 3 or greater and greater than 1.68x10(5) cfu P. gingivalis at the canine and premolar periodontium sample sites. Fourteen of 40 cats showed a serum antibody response to VPB 2814. Thirteen of these 14 cats had an overall periodontal grade of 3 or greater. Regression analysis of overall periodontal grade against the serum antibody response showed significant positive relationships for both VPB 2856 (r2 = 0.351; p<0.001) and VPB 2814 (r2 = 0.247; p<0.001). Regression analysis of the total colony forming units of feline strain P. gingivalis against the grade of serum antibody response showed a positive relationship for both VPB 2856 (r2 = 0.662; p<0.001) and VPB 2814 (r2 = 0.531; p<0.001). These data provide strong evidence that the recombinant proteinases of feline P. gingivalis expressed in E. coli clones VPB 2856 and VPB 2814 are associated with periodontal disease in cats.

Amino Acid Sequence↗
PubMed2000

Phospholipid analogues of Porphyromonas gingivalis.

Porphyromonas has lipids containing hydroxy acids and C16:0 and iso-C15:0 major monocarboxylic acids among others. Nothing is known of its individual phospholipid molecular species. The aim of this study was to determine molecular weights and putative identities of individual phospholipid molecular species extracted from Porphyromonas gingivalis (seven strains), P. asaccharolytica (one strain) and P. endodontalis (two strains). Cultures on Blood-Fastidious Anaerobe Agar were harvested, washed and freeze-dried. Phospholipids were extracted and separated by fast atom bombardment mass spectrometry (FAB MS) in negative-ion mode. Phospholipid classes were also separated by thin layer chromatography (TLC). The major anions in the range m/z 209-299 were consistent with the presence of the C13: 0, C15: 0, C16: 0 and C18: 3 mono-carboxylate anions. Major polar lipid anion peaks in the range m/z 618-961 were consistent with the presence of molecular species of phosphatidylethanolamine, phosphatidylglycerol and with unidentified lipid analogues. Porphyromonas gingivalis differed from comparison strains of other species by having major anions with m/z 932, 946 and 960. Unusually, a feline strain of P. gingivalis had a major peak of m/z 736. Selected anions were studied by tandem FAB MS which revealed that peaks with m/z 653 and 946 did not correspond to commonly occurring classes of polar lipids. They were however, glycerophosphates. It is concluded that the polar lipid analogue profiles obtained with Porphyromonas are quite different from those of the genera Prevotella and Bacteroides but reveal heterogeneity within P. gingivalis.

Anions↗
PubMed2000

Infection of the subcutis and skin of cats with rapidly growing mycobacteria: a review of microbiological and clinical findings.

Mycobacteria were isolated and characterised from 49 cats with extensive infections of the subcutis and skin. Cats were generally between 3 and 10 years of age, and female cats were markedly over-represented. All isolates were rapid-growers and identified as either Mycobacteria smegmatis (40 strains) or M fortuitum (nine strains). On the basis of Etest for minimum inhibitory concentration and/or disc diffusion susceptibility testing, all strains of M smegmatis were susceptible to trimethoprim while all strains of M fortuitum were resistant. M smegmatis strains were typically susceptible to doxycycline, gentamicin and fluoroquinolones but not clarithromycin. All M fortuitum strains were susceptible to fluoroquinolones, and often also susceptible to gentamicin, doxycycline and clarithromycin. Generally, M smegmatis strains were more susceptible to antimicrobial agents than M fortuitum strains. Treatment of mycobacterial panniculitis involves long courses of antimicrobial agents, typically of 3-6 months, chosen on the basis of in vitro susceptibility testing and often combined with extensive surgical debridement and wound reconstruction. These therapies will result in effective cure of the disease. One or a combination of doxycycline, ciprofloxacin/enrofloxacin or clarithromycin are the drugs of choice for long-term oral therapy.

Animals↗
PubMed2000

Effect of single bouts of moderate and high intensity exercise and training on equine peripheral blood neutrophil function.

The effects of single bouts of moderate (30 to 40 per cent VO(2)max) and high (115 per cent VO(2)max) intensity exercise on equine peripheral blood leucocyte function were evaluated by determining neutrophil phagocytosis and oxidative burst activity before and after treadmill exercise and training. Prior to all exercise tests, the possible effect of diurnal variation was evaluated in samples obtained from four resting horses. Subsequently eight horses underwent moderate and high intensity exercise protocols and then commenced a 17-week training period. High intensity exercise tests were repeated in week 10, after 7 weeks of endurance training, and in week 17, after a further 6 weeks of high intensity training. Time of sampling had a significant effect on neutrophil function for resting, untrained horses. Prior to training, moderate intensity exercise was associated with improved neutrophil phagocytosis and oxidative burst activity. High intensity exercise was associated with transient impairment of these responses. A similar reduction was not demonstrable following high intensity exercise in weeks 10 or 17 of training. Neutrophil function in week 17 was suppressed at all sampling times relative to results obtained in week 10, suggesting that high intensity training may have been associated with a general reduction in neutrophil function.

Animals↗
PubMed2000

The effect of high intensity exercise on the functional capacity of equine pulmonary alveolar macrophages and BAL-derived lymphocytes.

The effect of strenuous exercise on the functional capacity of pulmonary alveolar macrophages (PAM) and bronchoalveolar lavage-derived lymphocytes was determined in eight horses prior to and after 7 weeks of training. Strenuous exercise had no effect on the total cell count or the percentage of live cells in bronchoalveolar lavage (BAL) samples prior to or following training. However, training was associated with a significant increase in the total cell count of pre-exercise BAL samples and a significant reduction in the percentage of live cells in post-exercise samples. Strenuous exercise was associated with impaired phagocytosis by PAM after 7 weeks of training but had no effect on similar samples obtained from untrained horses. The oxidative burst activity of PAM was significantly increased following strenuous exercise for both untrained and trained horses. BAL -derived lymphocyte oxidative burst was similarly affected following training. These results suggest that strenuous exercise and training may influence pulmonary immune cell function.

Animals↗
PubMed2000

Mycobacterium genavense infection in two aged ferrets with conjunctival lesions.

Mycobacterium genavense infection was diagnosed in two adult ferrets. Disseminated mycobacteriosis was diagnosed in a castrated 5-year-old sable ferret with generalised peripheral lymph node enlargement and a proliferative lesion of the conjunctiva of the nictitating membrane. The diagnosis was based on characteristic cytology and sequence analysis of the 16S rRNA gene amplified using the polymerase chain reaction from fresh biopsy material. Therapy with rifampicin, clofazimine and clarithromycin probably cured the infection. An entire 4-year-old female ferret with conjunctival swelling, serous ocular discharge and swelling of the subcutaneous tissues of the nasal bridge was diagnosed as having M genavense infection on the basis of typical cytology, histopathology and sequence analysis of 16S rRNA amplicons from formalin-fixed paraffin-embedded tissue. This patient was treated successfully using rifampicin. Both ferrets subsequently died as a result of other disease conditions, 10 and 4 months following initiation of therapy, respectively. This is the first report documenting M genavense as a cause of disseminated mycobacterial disease in ferrets. Conjunctival involvement may be a feature of disseminated mycobacteriosis in the ferret. The possibility that these infections were the consequence of a ferret retrovirus infection should be considered further.

Animals↗
PubMed2000

Successful treatment of invasive nasal cryptococcosis in a ferret.

Invasive cryptococcal rhinitis due to Cryptococcus neoformans var gattii was diagnosed in a castrated, 5-year-old, albino ferret with subcutaneous swelling of the nasal bridge. The diagnosis was based on histology, needle aspirate cytology and positive culture on Sabouraud's dextrose agar and birdseed agar. The ferret was successfully treated using a long course of itraconazole (25 to 33 mg orally once daily with food) subsequent to surgical debulking of the lesion, using sequential cryptococcal antigen titre determinations to guide therapy.

Animals↗
PubMed2000

Use of multilocus enzyme electrophoresis to distinguish clinically important strains of Staphylococcus intermedius from the skin of dogs.

AIMS: To use multilocus enzyme electrophoresis to determine the genetic structure of Staphylococcus intermedius from normal skin of dogs and those isolated from a variety of disease conditions and to distinguish clinically important strains in dogs. METHODOLOGY: The diversity amongst 129 isolates of S intermedius from the skin and mucosa of 32 healthy dogs and 120 isolates from diseased sites in 120 individual dogs was examined using multilocus enzyme electrophoresis. Associations among ETs were examined to determine the diversity of isolates. RESULTS: Twenty two ETs were distinguished comprising 21 containing isolates from diseased sites and 11 containing isolates from normal dogs. The majority of isolates (171 of 249; 69% were located in two ETs (ET1 and ET 4), that were not distinguishable phenotypically. ET 1 contained 94 isolates (54 isolates from healthy dogs and 40 isolates from diseased sites) and ET 4 contained 77 isolates (46 from healthy dogs and 31 isolates from diseased sites). Further, 77.5% of isolates from healthy dogs were present in ET 1 and ET 4 and 59% of isolates from diseased dogs belonged to the same two ETs. There was only a small difference in genetic diversity among isolates taken from healthy dogs (11 ETs; H = 0.182) and those isolates taken from clinical specimens from diseased dogs (21 ETs; H = 0.218). Of the 21 ETs from diseased sites, ET 16 contained all six isolates from Staphylococcal Scalded Skin Syndrome in racing Greyhounds. CONCLUSIONS: The small difference in genetic diversity between isolates from the skin and mucosa of healthy dogs and isolates from various diseases, as well as the presence of the majority of isolates in two ETs, is consistent with the role of S intermedius as an opportunistic pathogen. The confinement of all Staphylococcal Scalded Skin Syndrome isolates within one ET is confirmation of this entity as a distinct disease of dogs.

Animals↗
PubMed2000

Towards an understanding of equine pleuropneumonia: factors relevant for control.

OBJECTIVE: To review relevant literature on factors associated with the development of equine pleuropneumonia. DESIGN: A review of the literature using a range of databases including Current Contents, Medline, ChemAbstracts, Biological Abstracts and CAB and a comprehensive search strategy which involved use of keywords, author and subject category searches. Additional sources included review of articles cited by key accumulated references. RESULTS: Since the early years of this century, many of the "gaps" in our knowledge of the pathogenesis of this disease have been filled. We now know that equine pleuropneumonia results from contamination of the lower respiratory tract with bacteria similar to the normal oropharyngeal microbiota of the horse and that transportation of any mode, especially over long distances (and consequently with no or short rest periods), is the single most important predisposing factor for this disease. This is associated with restraint of horses such that they are unable to lower their heads, which leads to increased opportunity for lower respiratory tract contamination and a reduced opportunity for clearance. Strenuous exercise also results in lower respiratory tract contamination and exercise subsequent to transportation exerts additive detrimental effects on the defenses of the lower respiratory tract. CLINICAL IMPLICATIONS: While modern veterinary medicine and surgery have significantly reduced the death rate from pleuropneumonia, horses that develop the disease have a high probability of not returning to their prior use. This underscores the importance of developing the most effective strategies for its prevention.

Animals↗
PubMed2000

In vitro antimicrobial susceptibilities of three Porphyromonas spp and in vivo responses in the oral cavity of cats to selected antimicrobial agents.

OBJECTIVES: To determine in vitro susceptibility of Porphyromonas gingivalis, P salivosa and P circumdentaria to seven antimicrobial agents by agar dilution and Epsilometer test methods and to assess the effectiveness of these antimicrobial agents in reducing the numbers of each Porphyromonas spp in the oral cavity of 16 domestic cats. DESIGN: A two-part prospective study involving in vitro antimicro-bial studies using Porphyromonas spp obtained from naturally occurring feline infections and in vivo antimicrobial response studies using client-owned cats with naturally occurring periodontal disease. PROCEDURE: Isolates (n = 25) of three feline Porphyromonas spp from the oral cavity and oral-associated disease were tested for their in vitro susceptibility to amoxycillin, amoxycillin-clavulanate, benzylpenicillin, clindamycin, doxycycline, erythromycin and metronidazole, using agar dilution and Epsilometer test methods. Digoxigenin-labelled whole chromosomal DNA probes directed against P gingivalis VPB 3492, P circumdentaria NCTC 12469T and P salivosa VPB 3313 were used to quantify organisms taken from two sample sites at the gingival margins of these cats prior to, and 5 days after, treatment with one of four commonly used antimicrobial products (amoxycillin-clavulanate, clindamycin, doxycycline or spiramycin-metronidazole). The response to treatment was assessed clinically for each cat. RESULTS: All isolates were susceptible in vitro to all seven antimicrobial agents using both methods. The numbers of P gingivalis were not reduced at the gingival sample sites by administration of amoxycillin-clavulanate for 5 days, although this treatment reduced the numbers of P salivosa and P circumdentaria to below detection levels in six of eight and two of three of sample sites, respectively; clinical improvement was not observed in cats treated with amoxycillin-clavulanate. Treatment with clindamycin, doxycycline or spiramycin-metronidazole resulted in clinical improvement and a marked reduction of all Porphyromonas isolates at the sample sites. CONCLUSION: The Epsilometer test is a simple and accurate method for determining the minimum inhibitory concentration for P gingivalis, P salivosa and P circumdentaria. All strains were susceptible in vitro to all the antimicrobial agents tested although clinical improvement of gingival disease was not noted with amoxycillin-clavulanate when given for 5 days at usual doses. This appears to be the first report of the disparity between the in vivo and in vitro susceptibility of oral bacterial strains to amoxycillin-clavulanate in the veterinary dental literature. This also appears to be the first report in which clinical and microbiological responses to commonly used antimicrobial agents for periodontal disease in cats has been documented and quantified. It was shown that treatment with clindamycin, spiramycin-metronidazole or doxycycline not only produced a substantial reduction in the number of Porphyromonas spp (in the majority of cases to below detection levels), but also resulted in substantial clinical improvement. This would indicate that these antimicrobial agents are useful adjunctive therapy to mechanical debridement in domestic cats.

Animals↗
PubMed2000

Bacterial infection of the lower respiratory tract in 34 horses.

OBJECTIVE: To investigate associations between the bacteriology and aspects of history, clinical presentation, outcome and pathology of lower respiratory tract disease of 34 horses. PROCEDURE: Detailed aerobic and anaerobic bacteriological investigations were performed on clinical specimens from horses with pneumonia, lung abscessation and necrotic pneumonia with or without pleurisy in an attempt to identify those bacteria that might contribute to the initiation and progression of infection. RESULTS: Bacteria were cultured from 33 of the 34 horses. In ten cases, only aerobic/facultatively anaerobic isolates were cultured while aerobic/facultatively anaerobic bacteria and obligately anaerobic bacteria were isolated in the other 23 cases. Moderate to large numbers of anaerobic bacteria were isolated only when the estimated duration of illness was at least five days. Bacteria were not cultured from 12 of the pleural fluid samples but were always cultured from pulmonary samples (either transtracheal aspirates from live horses or pulmonary lesions at necropsy). Streptococcus equi subsp zooepidemicus was isolated in the three cases where only one bacterial species was cultured. In the other 30 cases, multiple species were isolated. These included most often and in greatest numbers, Streptococcus equi subsp zooepidemicus, Pasteurellaceae, Escherichia coli, anaerobic cocci, Eubacterium fossor, Bacteroides tectum, Prevotella heparinolytica, Fusobacterium spp, and pigmented members of the genera Prevotella and Porphyromonas. Aerobic/facultatively anaerobic organisms were isolated from 97% of horses, while obligately anaerobic organisms were cultured from 68% of horses. CONCLUSION: There was no association between the isolation of any specific bacterium and the outcome of disease. However, obligately anaerobic bacteria (such as anaerobic cocci, Bacteroides tectum, P heparinolytica and Fusobacterium spp) and the facultatively anaerobic species Escherichia coli, were recovered more commonly from horses that died or were euthanased than from those that survived. There was an association between failure of horses to recover from pleuropneumonia and delay in diagnosis and initiation of treatment.

Animals↗
PubMed2000

Identification by 16S rRNA gene analyses of a potential novel mycobacterial species as an etiological agent of canine leproid granuloma syndrome.

PCR amplifications of the 16S rRNA gene were performed on 46 specimens obtained from 43 dogs with canine leproid granuloma syndrome to help determine its etiology. Sequence capture PCR was applied to 37 paraffin-embedded specimens from 37 dogs, and nested PCR was attempted on DNA from 9 fresh tissue specimens derived from 3 of the 37 aforementioned dogs and from an additional 6 dogs. Molecular analyses of the paraffin-embedded tissues and fresh tissue specimen analyses were performed at separate institutions. PCR products with identical sequences over a 350-bp region encompassing variable regions 2 and 3 of the 16S rRNA gene were obtained from 4 of 37 paraffin-embedded specimens and from all 9 specimens of fresh tissue originating from 12 of the 43 dogs. Identical sequences were determined from amplicons obtained from paraffin-embedded and fresh specimens from one dog. The consensus DNA sequence, amplified from paraffin-embedded tissue and represented by GenBank accession no. AF144747, shared highest nucleotide identity (99.4% over 519 bp) with mycobacterial strain IWGMT 90413 but did not correspond exactly to any EMBL or GenBank database sequence. With a probe derived from the V2 region of the novel canine sequence, reverse cross blot hybridization identified an additional four paraffin-embedded specimens containing the same novel sequence. In total, molecular methodologies identified the proposed novel mycobacterial sequence in 16 of 43 dogs with canine leproid granuloma syndrome, indicating that the species represented by this sequence may be the principal etiological agent of canine leproid granuloma syndrome.

Animals↗